Build An ‘Honest ETA’ Device–And Never Be Late Again [Video]

One moment, you’re on the way home from the office. The next, 30 minutes have slipped by because you tried to finish that one last thing–and oops, you forgot to tell your significant other.

I love my job as much as the next workaholic, but I hate ruining dinner plans and sleeping on the couch. So Popular Science and electronics maker littleBits have teamed up to create a project we’re calling the Honest ETA Device.

You can watch the video above to see it in action, or get the full project instructions at littleBits.cc, but it works like this: Bits are electronic building blocks that you snap together to make a circuit without the fuss of solder, resistors, and wires. Take a handful of specific bits from the Popular Science Super Bundle (a.k.a. the universe’s most versatile DIY electronics kit, and a great way to save nearly $40 on two of littleBits’ best-selling products), and assemble them. Next, create a couple of simple rules on IFTTT–a free service that helps you automate your digital existence. Then leave the project at home and head to work.

Your phone will share its GPS location with your littleBits project (specifically its cloudBit) and light up its bargraph bit as you near home. When you’re only minutes away, a tiny MP3 player and speaker plays a song of your choice. So the next time you leave the office (or don’t), your loved one at home will know approximately where you are in your daily commute.

Honest ETA is only the first of several great projects we’ve cooked up in partnership with littleBits. (Our next one has a high-stakes Indiana Jones flare to it.) You can follow along by picking up a kit at popsci.com/littleBits, and when you’re done, just pull the bits apart and move on to the next build.

You don’t have to wait around on us, of course: If you want to show off a great problem-solving project of your own, or have a fun design challenge for us to tackle, just mention @PopSci on Twitter with the hashtag #asklittlebits. We just might feature your tweet in a future video.

Editor’s note: We’ve partnered with littleBits to help you invent our way out of everyday problems with the Popular Science Super Bundle.